Dosing regimen for a selective s1p1 receptor agonist

ABSTRACT

The present invention relates to a dosing regimen for (R)-5-[3-chloro-4-(2,3-dihydroxy-propoxy)-benz[Z]ylidene]-2-([Z]-propylimino)-3-o-tolyl-thiazolidin-4-one.

FIELD OF THE INVENTION

The present invention relates to a dosing regimen for(R)-5-[3-chloro-4-(2,3-dihydroxy-propoxy)-benz[Z]ylidene]-2-([Z]-propylimino)-3-o-tolyl-thiazolidin-4-one(hereinafter also referred to as “Compound 1”).

DESCRIPTION OF THE INVENTION

The present invention provides a dosing regimen for Compound 1, by whichadverse effects are minimized in subjects/patients during initiation oftreatment, or upon re-initiation of treatment after drugdiscontinuation.

Compound 1 is a selective S1P₁ receptor agonist and oral administrationthereof results in a consistent, sustained, and dose-dependent reductionin the number of peripheral blood lymphocytes. Compound 1 has beendescribed to be useful in the treatment and/or prevention of diseases ordisorders associated with an activated immune system (see e.g., WO2005/054215 and WO 2009/115954). In particular, Compound 1 (INN:ponesimod) has shown clinical benefit in phase II trials in patientswith moderate to severe chronic plaque psoriasis and in patients withrelapsing-remitting multiple sclerosis (Olsson T. et al., Oral ponesimodin relapsing-remitting multiple sclerosis: a randomised phase II trial.J Neurol Neurosurg Psychiatry. 2014; 85 (11): 1198-1208; and VaclavkovaA. et al., Oral ponesimod in patients with chronic plaque psoriasis: arandomised, double-blind, placebo-controlled phase 2 trial. Lancet.2014; 384 (9959): 2036-2045). Compound 1 may be prepared according toany procedure as disclosed in WO 2005/054215, WO 2008/062376, and WO2014/027330.

WO 2010/046835 discloses different crystalline forms of Compound 1; itis to be understood that the present invention encompasses Compound 1 inany form including amorphous as well as crystalline forms of Compound 1.It is further to be understood that crystalline forms of Compound 1encompasses all types of crystalline forms of Compound 1 includingpolymorphs of the mere molecule, solvates and hydrates, molecular saltsand co-crystals (when the same molecule can be co-crystallized withdifferent co-crystal formers) provided they are suitable forpharmaceutical administration. In a preferred embodiment, Compound 1 isin crystalline form A or C as described in WO 2010/046835. In a mostpreferred embodiment, Compound 1 is in crystalline form C.

Repeated daily oral dosing of 5 mg or more of Compound 1 to humansresults in a consistent, sustained, and dose-dependent reduction in thenumber of peripheral blood lymphocytes. It has been surprisingly found,however, that the selective S1P₁ receptor agonist Compound 1 transientlyreduces heart rate in humans, with maximal effects 1-3 hours afteradministration. In some individuals this is accompanied by similarlytransient increases in the PR interval in the electrocardiogram (ECG),and an associated irregular heart rhythm (so-called Wenckebach rhythm).Occasional fatigue or dizziness also occur in the post-dose period. Allof these effects wane with repeated dosing. The acute effects on e.g.heart rate, atrioventricular conduction, or fatigue and dizziness areundesirable, and methods to minimize these effects would be valuable formaximizing the tolerability and safety of Compound 1 and minimizingassociated monitoring requirements in the early phase of dosinginitiation, or, after a drug interruption, at re-initiation of drugtherapy.

The subject matter of the present invention therefore provides a dosingregimen for Compound 1 which minimizes the incidence or severity ofadverse effects during initiation of treatment or upon re-initiation oftreatment after drug discontinuation. WO 2009/115954 discoses a dosingregimen for selective S1P₁ receptor agonists such as for exampleCompound 1. In clinical phase II studies, Compound 1 was administeredaccording to a dosing regimen herein after also referred to as regimen Bwhich consisted of a once daily oral administration of Compound 1 at adose of 10 mg for 7 days followed by 20 mg on day 8 (Olsson T. et al.,Oral ponesimod in relapsing-remitting multiple sclerosis: a randomisedphase II trial. J Neurol Neurosurg Psychiatry. 2014; 85 (11): 1198-1208;and Vaclavkova A. et al., Oral ponesimod in patients with chronic plaquepsoriasis: a randomised, double-blind, placebo-controlled phase 2 trial.Lancet. 2014; 384 (9959): 2036-2045). However, the dosing regimen of thepresent invention exhibits advantages compared to dosing regimen B (seeExperimental Part below). Using the novel up-titration regimen accordingto the present invention, the cardiodynamic first-dose and subsequenteffects and the safety and tolerability of Compound 1 are mitigatedcompared to the previous up-titration regimen.

i) In particular, the present invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use in the treatment of adisease or disorder associated with an activated immune system, whereinduring initiation of treatment, or upon re-initiation of treatment afterdrug discontinuation, Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by

(a) the maintenance dose of 10 mg of Compound 1 to be administeredorally once daily from day 12 onwards; or

(b) 10 mg of Compound 1 to be administered orally once daily for 2, 3 or4 days (i.e., on days 12 and 13; days 12, 13, and 14; or days 12, 13,14, and 15), especially for 3 days (i.e., on days 12, 13, and 14),followed by the maintenance dose of 20 mg of Compound 1 to beadministered orally once daily (i.e., from the day following the day ofthe last administration of the 10 mg dose onwards).

For clarity reasons it is noted that the once daily oral doses referredto in the above embodiment i) refer to the amount of Compound 1 in itsfree form. In case that for example a pharmaceutically acceptable saltof Compound 1 is used, the amounts given above will need to be adaptedaccordingly. In a preferred embodiment of the present invention Compound1 is administered in its free form.

The above sub-embodiment i) (b), i.e. the up-titration of Compound 1 tothe maintenance dose of 20 mg p.o. once daily, is preferred, especiallyin case Compound 1 is administered as monotherapy and especially in caseof monotherapy for the treatment of multiple sclerosis. However, it isto be understood that the dosing regimen according to sub-embodiment i)(b) does not exclude that the maintenance dose of 20 mg p.o. once dailyis later lowered, to e.g. 10 mg p.o. once daily, for e.g. safety reasonsif, for example, the number of peripheral blood lymphocytes falls belowa critical limit.

The production of oral pharmaceutical compositions of Compound 1 can beeffected in a manner which will be familiar to any person skilled in theart (see for example Remington, The Science and Practice of Pharmacy,21st Edition (2005), Part 5, “Pharmaceutical Manufacturing” [publishedby Lippincott Williams & Wilkins]) by bringing Compound 1 or apharmaceutically acceptable salt thereof into a galenical administrationform together with suitable, non-toxic, inert, pharmaceuticallyacceptable solid or liquid carrier materials and, if desired, usualpharmaceutical adjuvants.

ii) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according toembodiment i), wherein Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by 10mg of Compound 1 to be administered orally once daily for 2, 3 or 4days, especially for 3 days; followed by the maintenance dose of 20 mgof Compound 1 to be administered orally once daily.

iii) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according toembodiment i), wherein Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by 10mg of Compound 1 to be administered orally once daily on days 12, 13,and 14; followed by the maintenance dose of 20 mg of Compound 1 to beadministered orally once daily from day 15 onwards.

iv) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according toembodiment i), wherein Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10;

and 9 mg of Compound 1 on day 11; followed by the maintenance dose of 10mg of Compound 1 to be administered orally once daily from day 12onwards.

v) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis selected from the group consisting of rejection of transplantedorgans such as kidney, liver, heart, lung, pancreas, cornea, and skin;graft-versus-host disease; autoimmune syndromes including rheumatoidarthritis, multiple sclerosis, inflammatory bowel diseases such asCrohn's disease and ulcerative colitis, psoriasis, psoriatic arthritis,thyroiditis such as Hashimoto's thyroiditis, and uveo-retinitis; atopicdiseases such as rhinitis, conjunctivitis, and dermatitis; asthma; typeI diabetes; post-infectious autoimmune diseases including rheumaticfever and post-infectious glomerulonephritis; solid cancers; and tumormetastasis.

vi) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis selected from the group consisting of rejection of transplantedorgans selected from kidney, liver, heart and lung; graft-versus-hostdisease; autoimmune syndromes selected from rheumatoid arthritis,multiple sclerosis, psoriasis, psoriatic arthritis, Crohn's disease, andHashimoto's thyroiditis; and atopic dermatitis.

vii) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis graft-versus-host disease.

viii) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis chronic graft-versus-host disease.

ix) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis multiple sclerosis.

x) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis relapsing multiple sclerosis.

xi) A further embodiment of the invention relates to Compound 1, or apharmaceutically acceptable salt thereof, for use according to any oneof embodiments i) to iv), wherein the disease or disorder to be treatedis relapsing-remitting multiple sclerosis.

Based on the dependencies of the different embodiments as disclosedhereinabove, the following embodiments are thus possible and intendedand herewith specifically disclosed in individualized form: i), ii)+i),iii)+i), iv)+i), v)+i), v)+ii)+i), v)+iii)+i), v)+iv)+i), vi)+i),vi)+ii)+i), vi)+iii)+i), vi)+iv)+i), vii)+i), vii)+ii)+i), vii)+iii)+i),vii)+iv)+i), viii)+i), viii)+ii)+i), viii)+iii)+i), viii)+iv)+i),ix)+i), ix)+ii)+i), ix)+iii)+i), ix)+iv)+i), x)+i), x)+ii)+i),x)+iii)+i), x)+iv)+i), xi)+i), xi)+ii)+i), xi)+iii)+i), and xi)+iv)+i).

In the list above, the numbers refer to the embodiments according totheir numbering provided hereinabove whereas “+” indicates thedependency from another embodiment. The different individualizedembodiments are separated by commas. In other words, “viii)+iii)+i)” forexample refers to embodiment viii) depending on embodiment iii)depending on embodiment i), i.e. embodiment “viii)+iii)+i)” correspondsto the dosing regimen of embodiment i) further limited by the featuresof the embodiments iii) and viii).

The present invention also relates to a method of reducing the number ofperipheral blood lymphocytes in a human subject in need thereof, whereinduring initiation of treatment, or upon re-initiation of treatment afterdrug discontinuation, Compound 1, or a pharmaceutically acceptable saltthereof, is administered to the human subject orally once daily asdescribed in any one of above embodiments i) to iv).

The general terms and expressions used hereinbefore and/or hereinafterpreferably have, within this disclosure, the following meanings:

The term “pharmaceutically acceptable salt” refers to salts that retainthe desired biological activity of the subject compound and exhibitminimal undesired toxicological effects. Such salts include inorganic ororganic acid and/or base addition salts depending on the presence ofbasic and/or acidic groups in the subject compound. For reference seefor example ‘Handbook of Pharmaceutical Salts. Properties, Selection andUse.’, P. Heinrich Stahl, Camille G. Wermuth (Eds.), Wiley-VCH, 2008 and‘Pharmaceutical Salts and Co-crystals’, Johan Wouters and Luc Quéré(Eds.), RSC Publishing, 2012.

The expression “upon re-initiation of treatment after drugdiscontinuation” means an interruption of the administration of Compound1, or a pharmaceutically acceptable salt thereof, of at least one, atleast two or preferably at least 3 days before treatment isre-initiated.

The term “p.o.” means oral administration.

For the sake of clarity, relapsing multiple sclerosis means relapsingforms of multiple sclerosis which includes forms of multiple sclerosiswith relapses. Examples of relapsing multiple sclerosis arerelapsing-remitting multiple sclerosis, secondary progressive multiplesclerosis with relapses, and progressive relapsing multiple sclerosis.

EXPERIMENTAL PART

In a single-center, double-blind, placebo-controlled, randomized,two-way cross-over study, 32 healthy subjects (15 males) receivedplacebo on Day 1 followed by multiple-dose administration of eitherponesimod or placebo (ratio 3:1). Ponesimod was administered alternatelyusing regimen A (incremental dose increase from 2 to 20 mg) or B (10 mgfor 7 days followed by a single-dose administration of 20 mg).Cardiodynamic (Holter and 12-lead ECG), pharmacokinetic, pharmacodynamic(total lymphocyte count), and safety variables were assessed.

Subjects

In this trial, 32 healthy male and female subjects (15 and 17,respectively; mean±standard deviation [SD] body weight was 73.4±11.5 kg)aged between 18 and 57 years (34±12.7 years) were enrolled and receivedponesimod or its matching placebo (3:1 ratio active:placebo). The healthof the subjects was assessed at the screening visit, which includedrecording of the medical history, medications taken during the 3 monthspreceding the screening visit, a physical examination, measurement ofbody weight and height, clinical laboratory tests, recording of vitalsigns, and standard ECG. At screening and prior to first dosing,subjects had to have PR interval<200 ms, heart rate (HR)>50 beats perminute (bpm), systolic (SBP) and diastolic (DBP) blood pressure 90-145and 50-90 mmHg, respectively, 24-h Holter ECG without clinicallyrelevant abnormalities, forced expiratory volume in 1 second (FEV₁) andforced vital capacity (FVC)>80% of the predicted value and FEV₁/FVC>70%,and a normal total lymphocyte count (>1000 total lymphocyte count/μL).Women of childbearing potential had to use two reliable methods ofcontraception and should not be pregnant or lactating.

Study Design

The enrolled subjects came to the study center for each treatment periodon Day -2 and participated in a run-in (all study procedures performedwithout study drug administration) on Day −1. On Day 1, subjects wererandomized to one of the two possible sequences of the two up-titrationregimens A and B (ratio 1:1). On Day 1, all subjects received placebo;the first study drug administration (or its matching placebo) occurredon Day 2. Regimen A consisted of the novel up-titration regimen:ponesimod was administered once daily (o.d.) orally at a dose of 2 mg onDay 2 and Day 3, 3 mg on Day 4 and Day 5, 4 mg on Day 6 and Day 7, 5 mgon Day 8, 6 mg on Day 9, 7 mg on Day 10, 8 mg on Day 11, 9 mg on Day 12,10 mg on Day 13 and Day 14, and 20 mg on Day 15. The reference regimen(regimen B) was based on previous studies (Olsson T. et al., Oralponesimod in relapsing-remitting multiple sclerosis: a randomised phaseII trial. J Neurol Neurosurg Psychiatry. 2014; 85 (11): 1198-1208; andVaclavkova A. et al., Oral ponesimod in patients with chronic plaquepsoriasis: a randomised, double-blind, placebo-controlled phase 2 trial.Lancet. 2014; 384 (9959): 2036-2045) and consisted of an o.d. oraladministration of ponesimod at a dose of 10 mg for 7 days (i.e., fromDay 2 to Day 8) and 20 mg on Day 9. From Day 10 to Day 15 subjectsreceived o.d. the matching placebo. In the placebo group (1:1 sexratio), subjects received placebo from Day 1 to Day 15. All treatmentswere administered at the same time in the morning (fasted condition)with approximately 240 mL of water.

The subjects remained in the clinic until at least the morning of Day 16of each treatment period. Subjects were discharged if HR was >45 bpmand >70% of the HR at baseline without any clinically relevant ECGabnormalities. There was a washout period of 12 to 14 days between thelast study drug administration (i.e., Day 15) in the first treatmentperiod and the first study drug administration in the second treatmentperiod. Subjects came back to the clinic 5-7 days after last study drugadministration at the end of each treatment period for the end-of-firstperiod (EOFP) visit and the end-of-study (EOS) visit.

Cardiodynamic Assessments

Cardiodynamic endpoints were assessed using Holter and 12-lead ECG. The24-h Holter recordings were performed on Day −1, Day 1, Day 2, Day 9,Day 13, and Day 15. The 12-h Holter recordings were performed on theother days. In addition, Holter data were used to estimate the areaunder the effect curve (AUEC) for HR. 12-lead ECGs were performed fromDay −1 to Day 16 at pre-dose and 1, 2, 3, 4, 5, 6, 8, 10, and 12 h afterstudy drug administration. An additional 12-lead ECG recording wasperformed at EOFP and EOS. Heart rate nadir, E_(max) (maximum decreaseof mean hourly HR from baseline, which was defined as the mean of thetime-matched assessments measured on Day −1 and Day 1 pre-dose), andoccurrence of values of interest (HR<45 bpm, HR decrease frombaseline >20 bpm, and PR interval increase from baseline >20 ms), andAV-blocks (i.e., PR interval >210 ms) were obtained with 12-lead ECG.

Safety and Tolerability

Safety and tolerability were evaluated by monitoring adverse events(AEs), vital signs measurements (supine blood pressure), pulmonaryfunction tests (PFTs; i.e., FEV₁ and FVC), clinical laboratory,physical, and neurological examinations. Recording of blood pressure wasperformed at the same time-points as 12-lead ECG.

Pharmacokinetic and Pharmacodynamic Assessments

Blood samples of about 3 mL were collected in ethylene di-amine tetraacetic acid tubes at pre-dose and 3 h after study drug administrationfrom Day 1 to Day 15 in each treatment period. After centrifugation,plasma was transferred into a polypropylene tube and stored at −21° C.(±5° C.) pending analysis. Plasma concentrations of ponesimod weredetermined using a validated liquid chromatography coupled to tandemmass spectrometry assay with a lower limit of quantification of 1 ng/mL(Brossard P. et al., Pharmacokinetics and pharmacodynamics of ponesimod,a selective S1P₁ receptor modulator, in the first-in-human study.British journal of clinical pharmacology. 2013; 76 (6): 888-896). Troughsamples were taken on Day −1, Day 3, Day 6, Day 9, Day 12, and Day 15 ofeach treatment period and at EOFP and EOS to assess total lymphocytecount by hemocytometry.

Statistical Analysis

Cardiodynamic and pharmacodynamic data are expressed as mean±SD.Repeated measure one-way ANOVAs followed by Tukey's multiple-comparisonstests were used to perform inter-group (i.e., placebo vs. regimen A vs.regimen B) comparisons. Student's t-tests were employed to performintra-group (baseline vs. treatment) comparisons. Differences wereconsidered to be statistically significant at p<0.05. SAS® version 9.2(SAS Institute, Cary, N.C., USA) was used for the statistical analysisand descriptive statistics of clinical data.

Results:

Cardiodynamic Endpoints

There was no relevant difference in mean hourly HR (Holter ECG) betweenDay −1 (run-in) and Day 1 (all subjects treated with placebo). On Day 1,the placebo effect on mean hourly HR was similar between each treatmentperiod. The first dose of ponesimod (Day 2) triggered a decrease in meanhourly HR from baseline. This effect was limited in subjects treatedwith placebo for whom the mean maximum decrease (±SD) was observed 2 hpost-dose (0±5.2 bpm, p>0.05 vs. baseline [baseline defined as the meanof the pre-dose assessments on Day −1 and Day 1]). The mean hourly HRreduction was more pronounced following ponesimod administration and thenadir was observed 2 h (−6±7.4 bpm, p<0.05 vs. baseline) and 3 h(−12±6.9 bpm, p<0.05 vs. baseline) following administration of ponesimodin regimen A and regimen B, respectively. The mean hourly HR returned topre-dose values 4-5 h after administration. This effect was againobserved on Day 3 (2 h post-dose) with placebo (−2±4.9 bpm, p>0.05 vs.baseline), regimen A (−8±5.3 bpm, p<0.05 vs. baseline), and regimen B(−9±5.7 bpm, p<0.05 vs. baseline). From Day 4 to the last day oftreatment, no further significant decreases were observed in mean hourlyHR following ponesimod administration. Assessments on Day 2 and Day 3showed that the HR nadir value was lower following administration ofponesimod with regimen B than regimen A (p<0.05) and placebo (p<0.05).

On Day 1, when all subjects received placebo, similar mean AUEC from 0to 12 h after dosing (AUEC₀₋₁₂) values were calculated in the differenttreatment groups (placebo: −33.3±32.7, treatment regimen A: −11.8±34.4,and treatment regimen B: −26.4±37.0 bpm·h). On Day 2, the firstadministration of ponesimod led to a decrease in HR that was reflectedby a lower mean AUEC₀₋₁₂ in both treatment regimen A (−70.7±38.7 bpm·h)and treatment regimen B (−128.6±63.3 bpm·h) than in the placebo group(−5.3±36.8 bpm·h, p<0.05 placebo vs. ponesimod). After the firstadministration, AUEC was significantly greater (i.e., lesser effect)following the up-titration regimen A compared to treatment regimen B(p<0.05). On Day 3, the mean AUEC₀₋₁₂ was still greater followingtreatment regimen A (−105.5±49.0 bpm·h) than following ponesimod 10 mg(−146.6±59.8 bpm·h, p<0.05).

These Holter data were supported by 12-lead ECG data. On Day 1, multiplecomparisons revealed that HR profiles were similar during the day: aslight decrease during the first 2 h after administration (˜−2.7 bpm)followed by an increase (−12 bpm, 5 h after placebo administration). OnDay 2, following ponesimod at a dose of 2 mg (regimen A) and 10 mg(regimen B), a significant decrease was observed 2 h post-dose and themean maximum change from baseline (baseline defined as the mean of thepre-dose assessments on Day −1 and Day 1) was −9±5.3 bpm (p<0.05) and−13±6.2 bpm (p<0.05), respectively. The first-dose effect on HRreduction was greater following regimen B compared to placebo (−4±7.6bpm, 2 h post-dose, p<0.05 vs. baseline) or regimen A (p<0.05). HRreturned to baseline values within 3 and 4 h post-dose followingtreatment regimen A and regimen B, respectively. On Day 3, a decrease inHR was observed 2 h after administration of the second dose of ponesimodat a dose of 2 mg (−9±5.2 bpm vs. baseline) or 10 mg (−10±5.1 bpm vs.baseline). This decrease was more pronounced when compared to placebo(nadir: −4±4.7 bpm, p<0.05 vs. baseline). These differences weresupported by the E_(max) values. From Day 4 to the last day ofadministration of ponesimod (i.e., Day 15 for regimen A and Day 9 forregimen B), the pre-dose HR values were slightly lower inponesimod-treated subjects (range: 56-60 bpm) compared to subjects whoreceived placebo (range 60-64 bpm) but the HR-time profile was similar.

The occurrence of HR<45 bpm (at any time during the regimen from 12-leadECG) was more pronounced in regimen B (58 events in 4 subjects) comparedto regimen A (20 events in 3 subjects). There were no subjects whoexperienced HR<45 bpm in the placebo group.

During the course of the study, occurrence of PR interval>210 ms waslower following placebo (33 events in 4 subjects) than regimen A (79events in 6 subjects) and regimen B (143 events in 8 subjects).

The occurrence of HR<45 bpm, HR decrease from baseline (baseline definedas the mean of the pre-dose assessments on Day −1 and Day 1) >20 bpm, PRinterval 200 ms, or PR interval increase from baseline (baseline definedas the mean of the pre-dose assessments on Day −1 and Day 1) >20 msduring the first 12 hours on Day 2 and the percentage of subjectsexperiencing at least one of these events was similar between placebo(15 events in 5 subjects, i.e., 31.3% of the subjects) and regimen A (14events in 6 subjects, i.e., 25% of the subjects). The number of eventsand subjects displaying at least one event was higher in regimen B (43events in 12 subjects, i.e., 50% of the subjects).

Analysis of 12-lead ECG abnormalities revealed that sinus bradycardiaoccurred more often following regimen B compared to regimen A (Table 1).Events of AV-block first degree, AV-block second degree, and QTprolonged were only reported following placebo and regimen B (Table 1).

TABLE 1 Overall incidence of 12-lead ECG abnormalities Regimen A RegimenB Placebo (N = 24)^(#) (N = 24)^(#) (N = 16^(†))^(#) Atrial rhythm 4(16.7)/19 2 (8.3)/12 5 (31.3)/7  Supraventricular 3 (12.5)/15  7(29.2)/29 2 (12.5)/19 extrasystoles Sinus bradycardia 3 (12.5)/3   3(12.5)/33 — Ventricular extrasystoles 1 (4.2)/1  3 (12.5)/3 3 (18.8)/21Short PQ —  6 (25.0)/147 1 (6.3)/1  QT prolonged —  6 (25.0)/142 7(43.8)/21 AV-block 1st degree —  6 (25.0)/130 4 (25.0)/27 AV-block 2nddegree — 1 (4.2)/1  1 (6.3)/1  Mobitz I Sinus arrhythmia — 12 (50.0)/9815 (93.8)/266 Atrial fibrillation — 1 (4.2)/1* — Sinus tachycardia — — 2(12.5)/4  Supraventricular rhythm — — 1 (6.3)/1  *Serious adverse event^(#)From Day 2 to EOFP or EOS visit ^(†)Two treatment periods pooledData are presented as number of subjects (percentage)/number of events.

Safety and Tolerability

The total number of AEs and intensity of these AEs were similar acrossthe different treatment groups. All AEs were of mild to moderateintensity. The most commonly reported AEs on ponesimod were headache,dizziness, and procedural site reaction, and these AEs were also amongthe most commonly reported by subjects in the placebo group. AEs ofspecial interest related to cardiac function such as sinus bradycardiaand palpitations were reported more frequently during regimen B comparedto regimen A. One serious AE of atrial fibrillation was reported 6 hafter administration of 20 mg ponesimod (regimen B). This event resolvedwithout sequelae within 24 h.

Vital Signs, PFTs, and Clinical Laboratory Evaluation

No differences were observed in blood pressure (BP) between Day −1 andDay 1 (placebo) for any treatment regimen. A decrease in SBP and DBP wasobserved following the first administration of ponesimod with regimen A(SBP: -4±4.4 and DBP: −7±5.3 mmHg) and regimen B (SBP: −5±7.7 and DBP:−10±4.4 mmHg). The decreases in SBP and DBP were similar as thosefollowing placebo (SBP: −7±12.5 and DBP: −6±5.7 mmHg). On Day 1(placebo), Day 2 (first administration of ponesimod) and along thecourse of the study, a similar number of subjects reported at least oneevent of SBP<90 mmHg. A decrease from baseline in SBP>20 mmHg occurredless often following ponesimod administered with treatment regimen Acompared to treatment regimen B and placebo. Both number of events andsubjects who experienced DBP<50 mmHg or decrease in DBP from baseline>15mmHg were much more pronounced in the ponesimod-treated groups comparedto placebo.

No treatment effect was observed on PFT variables and hematologyvariables (hemoglobin, hematocrit, red blood cell count, basophils,eosinophils, neutrophils, monocytes, and platelet count) although someout-of range values were reported for most subjects but none wereconsidered as clinically significant.

Pharmacokinetic and pharmacodynamic endpoints Using the up-titrationregimen A, trough and 3 h post-dose plasma concentrations steadilyincreased. Similar concentrations were reached in regimen A at 3 h afterthe second dose of 10 mg ponesimod (i.e., Day 14) and the 5^(th) dose of10 mg ponesimod in regimen B (Day 6). Visual inspection revealed thatthe 10 mg steady-state conditions with regimen B were attained on Day 6.Plasma concentration 3 h after 20 mg of ponesimod was similar in regimenA (Day 15: 144.0±36.9 ng/mL) and regimen B (Day 9: 144.0±41.9 ng/mL).

As expected by its mode of action, a decrease of circulating totallymphocyte count was observed after ponesimod initiation. In regimen A,the decrease was more gradual when compared to regimen B. On Day 3, themean percentage change from baseline (±SD) was greater with regimen B(−28.9±12.2%) than with regimen A (−11.6±10.2%, p<0.05) and placebo(−0.3±22.2%, p<0.05). On Day 6, the decrease from baseline in totallymphocyte count was more pronounced with either regimen A (−15.0±14.4%)or regimen B (−46.5±12.3%) than with placebo (−0.2±11.3%). Following thelast dose of 10 mg ponesimod, a similar decrease in total lymphocytecount was observed with regimen A (Day 15 [before administration of thedose of 20 mg], −50.8±12.1%) and regimen B (Day 9 [before administrationof the dose of 20 mg], −52.3±11.0%). Each individual total lymphocytecount returned to within the normal range (i.e., 80% of baseline) atEOFP and EOS.

1. A method of treating a disease or disorder associated with anactivated immune systems comprising administering(R)-5-[3-Chloro-4-(2,3-dihydroxy-propoxy)-benz[Z]ylidene]-2-([Z]-propylimino)-3-o-tolyl-thiazolidin-4-one(Compound 1), or a pharmaceutically acceptable salt thereof, to asubject in need thereof, for use in the treatment of a disease ordisorder associated with an activated immune system, wherein duringinitiation of treatment, or upon re-initiation of treatment after drugdiscontinuation, Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by (a)the maintenance dose of 10 mg of Compound 1 to be administered orallyonce daily from day 12 onwards; or (b) 10 mg of Compound 1 to beadministered orally once daily for 2, 3 or 4 days, followed by themaintenance dose of 20 mg of Compound 1 to be administered orally oncedaily.
 2. A method as in claim 1, wherein Compound 1, or apharmaceutically acceptable salt thereof, is to be administered to ahuman subject orally once daily as follows: 2 mg of Compound 1 on days 1and 2; 3 mg of Compound 1 on days 3 and 4; 4 mg of Compound 1 on days 5and 6; 5 mg of Compound 1 on day 7; 6 mg of Compound 1 on day 8; 7 mg ofCompound 1 on day 9; 8 mg of Compound 1 on day 10; and 9 mg of Compound1 on day 11; followed by 10 mg of Compound 1 to be administered orallyonce daily for 2, 3 or 4 days; followed by the maintenance dose of 20 mgof Compound 1 to be administered orally once daily.
 3. A method as inclaim 1, wherein Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by 10mg of Compound 1 to be administered orally once daily on days 12, 13,and 14; followed by the maintenance dose of 20 mg of Compound 1 to beadministered orally once daily from day 15 onwards.
 4. A method as inclaim 1, wherein Compound 1, or a pharmaceutically acceptable saltthereof, is to be administered to a human subject orally once daily asfollows: 2 mg of Compound 1 on days 1 and 2; 3 mg of Compound 1 on days3 and 4; 4 mg of Compound 1 on days 5 and 6; 5 mg of Compound 1 on day7; 6 mg of Compound 1 on day 8; 7 mg of Compound 1 on day 9; 8 mg ofCompound 1 on day 10; and 9 mg of Compound 1 on day 11; followed by themaintenance dose of 10 mg of Compound 1 to be administered orally oncedaily from day 12 onwards.
 5. A method as in claim 1, wherein thedisease or disorder to be treated is selected from the group consistingof rejection of transplanted organs such as kidney, liver, heart, lung,pancreas, cornea, and skin; graft-versus-host disease; autoimmunesyndromes including rheumatoid arthritis, multiple sclerosis,inflammatory bowel diseases such as Crohn's disease and ulcerativecolitis, psoriasis, psoriatic arthritis, thyroiditis such as Hashimoto'sthyroiditis, and uveo-retinitis; atopic diseases such as rhinitis,conjunctivitis, and dermatitis; asthma; type I diabetes; post-infectiousautoimmune diseases including rheumatic fever and post-infectiousglomerulonephritis; solid cancers; and tumor metastasis.
 6. A method asin claim 1, wherein the disease or disorder to be treated is selectedfrom the group consisting of rejection of transplanted organs selectedfrom kidney, liver, heart and lung; graft-versus-host disease;autoimmune syndromes selected from rheumatoid arthritis, multiplesclerosis, psoriasis, psoriatic arthritis, Crohn's disease, andHashimoto's thyroiditis; and atopic dermatitis.
 7. A method as in claim1, wherein the disease or disorder to be treated is graft-versus-hostdisease.
 8. A method as in claim 1, wherein the disease or disorder tobe treated is chronic graft-versus-host disease.
 9. A method as in claim1, wherein the disease or disorder to be treated is multiple sclerosis.10. A method as in claim 1, wherein the disease or disorder to betreated is relapsing multiple sclerosis.
 11. A method as in claim 1,wherein the disease or disorder to be treated is relapsing-remittingmultiple sclerosis.